Enhancing Chitosan Films for Egg Packaging Using Cellulose Nanocrystals and Sodium Montmorillonite Nanoparticles

Bio-based polymers are believed to often demonstrate insufficient barrier capacity and mechanical strength, especially in egg packaging processes. This current work attempted to improve the characteristics of chitosan (CS) films for egg packaging by incorporating cellulose nanocrystals (CNC) and sodium montmorillonite (MMT) nanoparticles. Such nanofillers added to the polymer matrix should reduce water vapor permeability and improve the mechanical properties of bio-nanocomposite films. Herein, coatings containing 5 wt% CNC or MMT incorporated into chitosan were applied to enhance the storability of fresh eggs over 5 weeks at ambient conditions. SEM images revealed that coatings were able to seal the eggshell pores, thereby minimizing mass transfer. After 5 weeks of storage, the Haugh unit (HU) of eggs treated with CS-CNC (67.1) and CS-MMT (64.8) appeared reasonably higher than that of control (35.2) and pure chitosan (52.1). The yolk index of eggs coated with CS-CNC (0.355) and CS-MMT (0.343) surpassed both control (0.263) and CS-coated eggs (0.308). However, pH levels in the albumen of eggs coated with CNC or MMT nanocomposite were significantly lower than others during storage. Potentially, chitosan-based nanocomposite coatings could be effective in preserving the internal quality of eggs, providing a somewhat efficient barrier against CO₂ loss with relative pH maintenance.